1. Field of the Invention
The present invention relates to respiratory assistance apparatus.
2. Background Art
It is known that apparatus of this type include a respiratory gas source, for example a pressurized gas bottle, a generator, etc., and controlled valve means which are fed by said respiratory gas source and, at their outputs, generate respiratory gas pulses whose period and duration they control.
Known apparatus of this type are individual and only make it possible to assist one patient.
By controlling the controlled valve means, the inhalation duration and the exhalation duration can be successively controlled over time, in accordance with the patient, while maintaining the desired dead times adjusted by an operator.
An individual apparatus of this type, consequently makes it possible to optimize the respiratory assistance to the patient who is connected to it. However, in the event of disasters or serious accidents involving a large number of casualties who simultaneously require respiratory assistance, it is essential to provide as many respiratory apparatus as there are casualties.
This is generally impossible, and so some victims cannot be assisted before they reach hospital. Of course, this endangers their health, and may even cause their death, even though they could have been saved if they could have been given prompt, even if incomplete, respiratory assistance.
It will, however, be noted that document U.S. Pat. No. 4,495,946 which describes a pulsed breathing apparatus of the type given above, mentions that said apparatus can be used for a plurality of patients at the same time, using a single common oxygen source and by virtue of a single controlled valve. It is quite clear that, in this case, the same breathing cycle is imposed on all the patients, which may be harmful or even fatal to some of them, without the possibility of any adjustment other than the used oxygen flow.